1. Field of the Invention
The invention relates to exploratory instruments and, more particularly, to endoscopic type instruments.
2. Description of the Related Art
Endoscopic type instruments have been developed to allow physicians and surgeons to view within a visually obscured portion of a body cavity. Physicians and surgeons in particular use endoscopic type instruments in a body to perform certain surgical procedures with limited trauma, disfiguration, expense, and hazards usually associated with conventional types of surgery performed through relatively large incisions.
Endoscopic type instruments may be constructed as rigid, semi-rigid, or flexible. Before the 1980's, segments of the urinary system such as the urethra, prostate and bladder were the anatomical areas that could only be examined and operated upon using substantially rigid endoscopes and/or conventional surgical procedure requiring large incisions. During the early 1980's, the introduction of new slimmer and longer endoscopes presented the field of urology with a major revolution by allowing the exploration of the ureter (the hollow tubular structure that leads the urine from the kidney to the urinary bladder) and upper urinary system within the kidney. These revolutionary instruments negated the need for a surgical procedure requiring a large incision. These new devices were named ureteroscopes and nephroscopes. Thus, the era of minimally invasive surgery had begun. These instruments were particularly helpful in removing kidney stones. Also, the advent of Extracorporeal Shock Wave Lithotripsy (stone fragmentation from outside of the body) made it necessary to dislodge and remove stone fragments from the kidney using an endoscopic type device in the ureter. During this time, the endoscopes were substantially rigid and their diameters were rather large, which had several limitations when entering and exploring a soft and curved conduit, such as the ureter.
Subsequently and towards the end of the 1980's, the incorporation of fiber optics into endoscopes permitted the reduction of the instrument's diameter and rendered the instrument's shaft some flexibility, thus overcoming “some” of the limitations of rigid endoscopes. This new generation of instruments were named “semi-rigid” miniscopes and made rigid scopes obsolete for most surgical procedures in the ureter and upper urinary tract, with the exception of percutaneous procedures in which rigid scopes are still used. These endoscopic type instruments, however, had many design and functionality limitations that do not facilitate diagnosis and surgery of body cavities, such as those in the upper urinary system. For example, rigid and semi-rigid endoscopes could not explore the upper urinary system within the kidney, thus, there was a risk of missing some pathology during diagnosis that might not be apparent by other imaging techniques such as x-rays, MRI, and CT scans, etc. Also, rigid and semi-rigid endoscopes were further inherently limited when performing surgical procedures that require flexibility.
By the end of the 1980's, “flexible” endoscopes were created to provide an opportunity to examine and operate on the upper urinary system. Currently, the semi-rigid and flexible endoscopes are the devices most commonly utilized for the ureter and upper urinary tract. The advantages of the flexible endoscopes are adaptability and finesse, or control of the device. The rigid, or even the semi-rigid, endoscopes do not permit exploration and intervention of the upper urinary tract within the kidney due to their inherent lack of adaptability and flexibility. For example, use of a rigid endoscope required penetration of the kidney during examination, or if entrance through the natural channels, then excessive rotation and maneuvering of the device is required, whereas the flexible endoscope has the versatility to maneuver through the urinary tract and directly into the kidney. Specifically, the rigid and semi-rigid endoscopes cannot properly explore the upper urinary system within the kidney; thus a diagnosis might be missed. Use of nonflexible endoscopes requires the surgeon to rotate the instrument to negotiate the passageways. The rigid and semi-rigid endoscopes are typically made of a hard material that can injure or lacerate the urinary system, if not used property, especially during the rotating maneuver. Therefore, examination within the natural anatomical curves of the urinary system ideally requires use of flexible instruments that can adapt and maneuver through, and to, the ureter passage instead of forcing the ureter passage to adapt to the shape of the instrument.
Flexible endoscopes, however, are typically very difficult to use since their flexibility makes insertion of the instrument difficult, and proper use in such anatomical sections such as the upper urinary system is beyond the typical user's experience level. Most urologists do not have the skill, sensitivity, dexterity, or expertise to operate with fully flexible endoscopes. Fully flexible endoscopic type instruments are difficult to insert due to their lower consistency and firmness because they are typically made from a soft plastic, or polymer like material formed around the fiber optics, which material bends easily. Also, in addition to where the insertion end of the instrument bends, the flexible instruments are easily breakable at the union of the handle area and the instrument's shaft. The instrument's excessive flexibility makes handling difficult and often results in the need for an extra pair of trained hands, such as those of a nurse or physician, for its introduction. Because of its difficulty of use, most urologists prefer the rigid or semi-rigid endoscopes in spite of their limitations. Therefore, urologists have sought an endoscopic type instrument that: is surgically friendly; has reduced difficulty of use; should increase the probability of success, while minimizing the risks during surgery. Therefore, the art has also sought a new generation of endoscopes that will improve and facilitate surgery upon the urinary system (including the upper urinary tract within the kidney, bladder, prostate and urethra) and minimize the risk of laceration and injury during surgical procedures. More specifically, the art has sought an instrument design that: can facilitate the insertion of the instrument into, and through, a delicate non-linear cavity such as a urinary tract; facilitate the exploration of the upper urinary tract in order to diagnose and surgically intervene anywhere in the urinary system; provides stability to avoid breakage during the procedure; provides easier mobility within the upper urinary system; and facilitates the introduction of different accessories with more precision.
The design and elements of a traditional face tip of an endoscopic type instrument, either rigid, semi-rigid or flexible, has changed very little since the first one was introduced. Basically they all include one or more of the following input/output ports: a working channel port to introduce operating accessories to perform a procedure; an optical image collector-conductor port, for example, a telescope port for viewing; a luminous conductor port, for example, an illumination fiberoptics port; and sometimes an irrigation & suction channel port. It is believed that with conventional endoscopes, the accessories are introduced before they can actually be observed within the urinary system. The conventional operating accessories exit port is located behind the optics created a “blind spot”; thus they enter the urinary system before the surgeon has visual control. In the medical setting, the exit of the accessories on the instrument's side is typically very close to the urinary tract wall. The surgeon's lack of view of the natural curves of the ureter, caused by the blind spot, can produce an inadvertent tear or perforation of the ureteral wall. Also, by exiting the operating tools on the side of the instrument, it obligates the surgeon to rotate the instrument in order to appropriately target the lesion, or the foreign body, to achieve the purpose of the exploration or the intervention. This maneuver, or “frequent rotation” may increase the risk of perforation and/or the inherent trauma by the instrument's insertion or pressure creating inflammation of the structures under exploration. Therefore, the art has sought an endoscopic type instrument wherein the working tool or accessories exit at the face tip, coincident with or in front of the viewing device to reduce the risk of laceration by allowing the surgeon to view the instrumental accessories as they exit either in front of the optics, lenses, or from the midsection of the instrument face tip
Endoscopic type instruments have typically ranged in complexity from simple viewing scopes which employ a light source and an ocular system, to relatively complex instruments having a light source, an image collection system, fluid channels, and a surgical or working tool channel. The required features employed in an endoscopic type instrument are determined in part by the requirements of the type of examination or surgery in which the instrument is used.
The light source for illuminating the site of interest is usually positioned outside the cavity. The light is communicated through the instrument by an illumination, or light conductor, usually formed of a fiber optic bundle. It is conceivable that the light conductor could be separate from the instrument itself. This would allow for use of an endoscope with a reduced diameter or would allow additional functions in a scope of a given diameter. No matter what additional use endoscopic type instruments have been put to, their examination properties remain their staple use. Conventional lenses for image collection and transmission generally require that the instrument be rigid or semi-rigid. Flexible endoscopic type instruments typically employ coherent optical fiber bundles wherein the opposite ends of the fibers are identically ordered. The image quality of lens based image collection and transmission is generally superior to image collection and transmission formed of fiber optics or fiber optics alone.
Endoscopic type instruments may be constructed to have fluid channels which may serve a variety of different purposes. For example, in certain procedures on the lungs, the fluid channel provides an air passage to allow the lung to breathe. In other procedures, the fluid channel may be used to insufflate, or inflate, a cavity in the body for better access to obtain a better view. In other procedures, a supply of cleansing fluid, such as water, may be used to clear away undesirable contaminant fluid, such as blood, from a location to facilitate inspection or to clean the image collector. A suction line is often used for removing fluids from the site. A working tool channel provides for the insertion of various working implements, or accessories, through the instrument such as forceps, scissors, punches, electrodes, lasers, and the like.
An endoscopic type instrument may include a typically tubular shaped shaft connected to a handle and viewing assembly which typically provide a mechanical coupling to which a viewing apparatus is connected. The typical endoscopic type instrument may include fluid channels extending through the shaft which communicate with external fluid connections on the handle and the assembly. A working tool port on the handle and viewing assembly typically communicates with a working tool channel in the shaft and may include a clamp or other support device to hold the working tool in place. An illumination port typically communicates with a light source. The light is normally transmitted from the viewing end or proximal end of the instrument to a light directing lens, or lenses, at the distal end. An optical collector including an objective lens is positioned at the distal end and passes the image through the image conductor to the handle and viewing apparatus through which the operator views the section of the cavity of interest. The objective lens, if used, is typically fixed and may be oriented along the longitudinal axis of the shaft or be angled off-axis for a view to the side. Some endoscopic type instruments have a fixed combination of functions, while others may be adapted to allow a selection of functions from a variety of working tools and viewing methodologies.
The handle and viewing apparatus of endoscopic type instruments usually accommodate various adapters for connecting various types of video, or other imaging, devices. In some cases, an image multiplexer is utilized to separate the image for simultaneous display on an optical viewer used for direct viewing and a video imager to televise or record the procedure.
An endoscopic type instrument having only a single optical collector-optical conductor or single telescope, alone, creates only a two-dimensional, or monoscopic, view of the region under inspection. This often results in a lack of depth perception for the user of the instrument, making it difficult to perform an accurate inspection or surgery. Three dimensional, or 3-D, viewing would allow for more precise viewing when maneuvering inside such anatomical features as the urinary tract, and would allow for better identification and perception of dimensions and distances from the instrument tip to the object in question, especially where the instrument is being used in a cavity containing a fluid. Although, three-dimensional, or stereoscopic, laproscopic type instruments, such as steromicroscopes, have been developed for creating a three-dimensional view of the object or region under inspection these are not suited for use in endoscopics. These instruments are provided with a pair of optical pathways or channels for transmitting a plurality of simultaneously gathered images of the object of interest to a stereoscopic viewer. Traditionally, the stereoscopic viewer has had microscope-like eyepieces through which the viewer views the respective images. The eyepieces are arranged so that the viewer's eyes provide the necessary convergence to combine the images into a stereoscopic view. Convergence of right eye and left eye images of an object is done in normal stereopsis by converging the optical axes with the eyes or optical/mechanical means to accomplish convergence of the right and left images so that the brain receives and perceives the images as sufficiently close together for the brain to combine the images as a single three-dimensional image. The stereomicroscope is an example of such an optical/mechanical device. Although the human brain can converge and “fuse” two separate views if the separation between the images is not too great, this is not easy or comfortable to achieve in practice. In typical stereo-microscopes, the problem is solved by using two converging optical systems. However, this is not a practical solution in endoscopic type systems where the necessary convergence at very short focal lengths is compounded by the need to keep the overall diameter of the system as small as possible so that the endoscope tube can be inserted through a single minimum size surgical incision, minimizing invasive procedures. Also, traditionally, where a video viewing system is used, the two parallel optical systems used in such arrangements do not converge the images and provide two separate images or video pictures.
Accordingly, prior to the development of the present invention, it is believed that there has been no endoscopic type instrument which: has the versatility of a flexible endoscope, while retaining the controllability of a semi-rigid or rigid endoscope; has an instrument shaft which is both rigid for a portion of its length and flexible for a portion of its length; which avoids, or reduces, the necessity for rotation of the instrument when targeting is required and while working inside delicate cavities; provides three dimensional imaging; does not have a blind spot associated with the instrument when working tools or accessories exit the instrument. Therefore, the art has sought an endoscopic instrument, or endoscope, which has the versatility of a flexible endoscope, while retaining the controllability of a semi-rigid or rigid endoscope; has an instrument shaft which has a rigid portion and a flexible portion; prevents, or reduces, the necessity for rotation of the instrument when targeting is required and while working inside delicate cavities; provides three dimensional imaging in the viewing system; and does not have a blind spot at the point where the working tools or accessories exit the instrument.